The Gyron Junior was a two-fifths flow scale version of the existing Gyron engine. It started as Project Study number 43 in 1954 and the first prototype ran in August 1955.[2]
It powered the Blackburn Buccaneer S.1 twin-engined Naval strike aircraft. The engine was rather unreliable and considered short of thrust.[3] The later Buccaneer S.2 used the more powerful Rolls-Royce Spey engine.
The engine had variable inlet guide vanes, as used on many other engines, necessary for accelerating from idle to high thrust. However, on the Gyron Junior, positioning of the vanes was not reliable and could cause surging which, in turn, could prevent accelerating to higher thrust levels.[3] A possibly unique feature on this engine was valve-controlled cooling air to the turbine blades. The engine had to supply air for the aircraft's boundary layer control system and the resulting thrust loss was unacceptable. To regain the thrust the turbine temperature limit was raised by using turbine blade cooling, selected only with blowing on.[4]
In December 1970 a Buccaneer was lost after one engine surged and failed to accelerate on an overshoot and a week later another aircraft was lost after an uncontained engine failure. This last accident brought to an end the use of Gyron Junior.[3]
Two Gyron Juniors, with afterburners, were also used on the Bristol 188 Mach 2 supersonic research aircraft. The 188 was originally intended to have the Rolls-Royce Avon but the half ton lighter Gyron Junior was substituted in June 1957. This engine was one of the first in the world to have infinite variation of thrust right up to full reheat; other manufacturers increased thrust in discrete steps.[5] The program was terminated early without achieving the high-speed high-temperature trials that had been intended. Limitations included poor fuel consumption of the Gyron Junior and engine surging. Fuel limitations restricted the time spent at its maximum speed, Mach 1.95, to a few minutes. This was not long enough to achieve the required stabilized temperatures in "thermal soaking" tests.
(Mk.101) Interim production stage, used on Buccaneer S. Mk.1.[6] Variable inlet and guide vane, annular manifold for flap blowing, 121 in (3.1 m) long overall
Gyron Junior DGJ.10
Exhibited in 1958 at Farnborough, longer than the DJG.1[7][6]
Gyron Junior DGJ.10R
(or P.S.50) highly augmented afterburning version for the Bristol 188, dry thrust 10,000 lb, wet thrust 14,000 lb (62.3 kN). Added zero stage and two rows of variable stators. Variable nozzle with convergent, convergent/parallel or convergent/divergent configuration depending on reheat selection and aircraft speed. Overall length 191 in (4.9 m)[8]
^Jackson, A.J. (1968). Blackburn Aircraft since 1909. London: Putnam Publishing. p. 494. ISBN0-370-00053-6.
^James, Derek N. (1971). Gloster Aircraft since 1917. London: Putnam Publishing. pp. 322, 326, 370. ISBN0-370-00084-6.
^Gatwick Aviation Museum - Buccaneer S.1 16 March 2016 at the Wayback Machine Retrieved: 23 February 2012
External links
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January 07, 2023
havilland, gyron, junior, military, turbojet, engine, design, 1950s, developed, havilland, engine, company, later, produced, bristol, siddeley, gyron, junior, scaled, down, derivative, havilland, gyron, gyron, junior, havilland, aircraft, museumtype, turbojetm. The de Havilland Gyron Junior was a military turbojet engine design of the 1950s developed by the de Havilland Engine Company and later produced by Bristol Siddeley The Gyron Junior was a scaled down derivative of the de Havilland Gyron Gyron Juniorde Havilland Gyron Junior at the de Havilland Aircraft MuseumType TurbojetManufacturer de Havilland Engine CompanyFirst run August 1955 1 Major applications Blackburn Buccaneer Bristol 188Number built 89Developed from de Havilland Gyron Contents 1 Design and development 2 Variants 3 Applications 4 Engines on display 5 Specifications Gyron Junior DGJ 10 5 1 General characteristics 5 2 Components 5 3 Performance 6 See also 7 References 8 External linksDesign and development EditThe Gyron Junior was a two fifths flow scale version of the existing Gyron engine It started as Project Study number 43 in 1954 and the first prototype ran in August 1955 2 It powered the Blackburn Buccaneer S 1 twin engined Naval strike aircraft The engine was rather unreliable and considered short of thrust 3 The later Buccaneer S 2 used the more powerful Rolls Royce Spey engine The engine had variable inlet guide vanes as used on many other engines necessary for accelerating from idle to high thrust However on the Gyron Junior positioning of the vanes was not reliable and could cause surging which in turn could prevent accelerating to higher thrust levels 3 A possibly unique feature on this engine was valve controlled cooling air to the turbine blades The engine had to supply air for the aircraft s boundary layer control system and the resulting thrust loss was unacceptable To regain the thrust the turbine temperature limit was raised by using turbine blade cooling selected only with blowing on 4 In December 1970 a Buccaneer was lost after one engine surged and failed to accelerate on an overshoot and a week later another aircraft was lost after an uncontained engine failure This last accident brought to an end the use of Gyron Junior 3 Two Gyron Juniors with afterburners were also used on the Bristol 188 Mach 2 supersonic research aircraft The 188 was originally intended to have the Rolls Royce Avon but the half ton lighter Gyron Junior was substituted in June 1957 This engine was one of the first in the world to have infinite variation of thrust right up to full reheat other manufacturers increased thrust in discrete steps 5 The program was terminated early without achieving the high speed high temperature trials that had been intended Limitations included poor fuel consumption of the Gyron Junior and engine surging Fuel limitations restricted the time spent at its maximum speed Mach 1 95 to a few minutes This was not long enough to achieve the required stabilized temperatures in thermal soaking tests Variants EditRef 1 Gyron Junior DGJ 1 or P S 43 Gyron Junior DGJ 2 Mk 101 Interim production stage used on Buccaneer S Mk 1 6 Variable inlet and guide vane annular manifold for flap blowing 121 in 3 1 m long overall Gyron Junior DGJ 10 Exhibited in 1958 at Farnborough longer than the DJG 1 7 6 Gyron Junior DGJ 10R or P S 50 highly augmented afterburning version for the Bristol 188 dry thrust 10 000 lb wet thrust 14 000 lb 62 3 kN Added zero stage and two rows of variable stators Variable nozzle with convergent convergent parallel or convergent divergent configuration depending on reheat selection and aircraft speed Overall length 191 in 4 9 m 8 Gyron Junior DGJ 20 6 Applications EditBlackburn Buccaneer S 140 aircraft built 9 Bristol 188Only 2 builtGloster JavelinTesting only 1 production FAW Mk 1 modified 10 Saunders Roe SR 177Intended application not builtEngines on display EditA de Havilland Gyron Junior is on display at the de Havilland Aircraft Museum London Colney Hertfordshire A D H Gyron Junior is on public display at East Midlands Aeropark Also on display at the Gatwick Aviation Museum Charlwood Surrey two running engines can also be found here fitted to Buccaneer S 1 XN923 11 Specifications Gyron Junior DGJ 10 Edit Rear view Data from Gunston and Jane s All the World s Aircraft 1962 63 1 6 General characteristics Type Single spool after burning turbojet Length 102 9 in 261 4 cm Diameter 41 1 in 104 4 cm Dry weight 3 100 lb 1 400 kg Components Compressor 7 stage axial flow with Variable Inlet Guide Vanes VIGV Combustors Annular combustion chamber with 13 spill type burners Turbine Two stage axial flow Fuel type Aviation kerosene Oil system Pressure spray splash with scavengingPerformance Maximum thrust 10 000 lbf 44 kN dry 14 000 lbf 62 kN wet at sea level 20 000 lbf 89 kN at M2 5 at 36 000 ft 11 000 m Overall pressure ratio DGJ 1 6 4 1 1 Air mass flow DGJ 1 123 lb s 56 kg s Thrust to weight ratio 3 23 dry 4 52 wet at sea level 6 45 at M2 5 at 36 000 ft 11 000 m See also EditRelated development de Havilland GyronComparable engines Armstrong Siddeley SapphireRelated lists List of aircraft enginesReferences Edit a b c d Gunston Bill 1989 World Encyclopaedia of Aero Engines Wellingborough Patrick Stephens p 52 ISBN 1 85260 163 9 Flight Aeroengines 1960 a b c A Passion For Flying Tom Eeles Pen amp Sword Books Ltd 2008 ISBN 978 1 84415 688 7 p 42 From Spitfire To Eurofighter Roy Boot Airlife Publishing Ltd Shrewsbury lt ISBN 1 85310 093 5 p 133 1962 0700 Flight Archive www flightglobal com Archived from the original on 24 February 2016 a b c d Taylor John W R FRHistS ARAeS 1962 Jane s All the World s Aircraft 1962 63 London Sampson Low Marston amp Co Ltd A New Gyron Junior PDF Flight August 1958 Aeroengines 1960 Flight 18 March 1960 Jackson A J 1968 Blackburn Aircraft since 1909 London Putnam Publishing p 494 ISBN 0 370 00053 6 James Derek N 1971 Gloster Aircraft since 1917 London Putnam Publishing pp 322 326 370 ISBN 0 370 00084 6 Gatwick Aviation Museum Buccaneer S 1 Archived 16 March 2016 at the Wayback Machine Retrieved 23 February 2012External links Edit Wikimedia Commons has media related to De Havilland Gyron Junior Photo of DH Gyron Junior Photo of Gyron Junior Gyron Junior on LeteckeMotory cz cs Retrieved from https en wikipedia org w index php title De Havilland Gyron Junior amp oldid 1125171205, wikipedia, wiki, book, books, library,
